diff --git a/src/include/86box/nv/vid_nv_rivatimer.h b/src/include/86box/nv/vid_nv_rivatimer.h
index 8ccc0f0df..a4fe85e92 100644
--- a/src/include/86box/nv/vid_nv_rivatimer.h
+++ b/src/include/86box/nv/vid_nv_rivatimer.h
@@ -63,7 +63,7 @@ typedef struct rivatimer_s
     double                  value;          // The current value of the rivatimer
     bool                    running;        // Is this RivaTimer running?
     struct rivatimer_s*     next;           // Next RivaTimer
-    void                    (*callback)(void);  // Callback to call on fire
+    void                    (*callback)(double real_time);  // Callback to call on fire
     #ifdef _WIN32
     LARGE_INTEGER           starting_time;  // Starting time.
     #else
diff --git a/src/video/nv/nv_rivatimer.c b/src/video/nv/nv_rivatimer.c
index ee8c13916..44e5901d1 100644
--- a/src/video/nv/nv_rivatimer.c
+++ b/src/video/nv/nv_rivatimer.c
@@ -34,7 +34,7 @@ rivatimer_t* rivatimer_tail;        // The tail of the rivatimer list.
 /* Functions only used in this translation unit */
 bool rivatimer_really_exists(rivatimer_t* rivatimer);   // Determine if a rivatimer really exists in the linked list.
 
-void rivatimer_init()
+void rivatimer_init(void)
 {
     // Destroy all the rivatimers.
     rivatimer_t* rivatimer_ptr = rivatimer_head;
@@ -162,7 +162,7 @@ void rivatimer_destroy(rivatimer_t* rivatimer_ptr)
     rivatimer_ptr = NULL; //explicitly set to null
 }
 
-void rivatimer_update_all()
+void rivatimer_update_all(void)
 {
     rivatimer_t* rivatimer_ptr = rivatimer_head;